EPJ H Highlight - From Hole Theory to Quantum Field Theory

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Published on 08 May 2026

New analysis reconstructs a pivotal transition in physicists' understanding of fermionic quantum fields, tracing how Ettore Majorana's largely overlooked 1937 work helped shape the modern framework of Quantum Field Theory

Since its earliest origins in the 1920s, Quantum Field Theory (QFT) has come to underpin our understanding of the universe's most fundamental particles and forces. Among the most important stages in its development was a period from 1933 to 1937, when relativistic fermions were widely studied in the context of Dirac's Hole theory – which suggested that a vacuum exists as a 'sea' of negative energy states, each fully occupied by an electron. As this framework was gradually superseded, QFT began its gradual and consistent construction.

Through new analysis published in EPJ H: Historical Perspectives on Contemporary Physics, Francesco Vissani at The National Institute for Nuclear Physics (INFN), Italy, reconstructs the crucial stages of this transition, highlighting the seminal role played by Italian theorist Ettore Majorana.

By 1941, Pauli's influential synthesis had solidified the modern framework of quantum field theory. This cemented the concept that two or more identical fermions cannot occupy the same quantum state – an idea that became a cornerstone of QFT in its current form. However, this likely wouldn't have happened without Majorana's 1937 work, which offered a decisive conceptual alternative to Dirac's Hole theory.

Through work which has since been largely overlooked, Majorana argued that fermions must 'anti-commute', so that swapping the order in which two identical fermions are created at the same point nullifies the result. As a result, the state cannot exist in the first place. By integrating the rules of the Pauli exclusion principle directly into the mathematics of the fermion field, this concept offered a far cleaner route than Dirac's Hole theory required.

By examining the progress of the many researchers whose work led to Majorana's final result, Vissani's analysis ultimately sheds new light on a line of research which came to transform our understanding of the quantum world. Beyond its historical significance, Majorana's approach retains a practical value today. By offering a conceptually cleaner framework than its predecessors, it continues to provide physics students and researchers alike with a clearer map for navigating some of the most demanding ideas in modern physics.